A variety of different types of input devices are used in electronic devices and systems. For examples, a variety of object sensing devices, including touchpads and touchscreens have been used as input devices computers, mobile devices, gaming devices, etc. In such devices a variety of technics can be used to determine the presence and/or location of one or more input objects proximate to the touch surface. These determined object presences and locations can then be used to generate a variety of user interface inputs and controls.
One continuing issue with such input devices is touch detection. Specifically, it is desirable in many applications to accurately determine when an input object has physically touched a surface. For example, it may be desirable to reliably determine that a finger has touched the touch surface be before an input is confirmed. Unfortunately, in many devices it can be difficult to distinguish between an input object that is touching the surface and one that is merely hovering closely to the surface. For example, in some input devices the resolution may be insufficient to distinguish between an object that is touching and one that is merely hovering. This can be especially problematic when the input object is a human finger that can have significant variation in size and shape.
In such input devices a hovering object may be incorrectly determined to be touching and an unwanted or inadvertent input generated as a result. In other cases a touch of the surface can be missed and no input generated when such an input was desired by the user. In either case the incorrect determination of a touch of the surface can lead poor usability and annoyance by the user.
Therefore, what is needed are improved devices and methods for reliably determining when an input object has touched a touch surface in an input device.